Alignment device

Abstract

An alignment device comprising a movable table, a plurality of movable support means for movably supporting the movable table, means for reading a recognition mark, and a control means for controlling the drive of the movable support means based on information from the recognition means, wherein each movable support means comprises means having a pair of support blocks each provided to be able to contact / separate with / from the movable table and a pair of piezoelectric actuators each provided with expansible first, second and third piezoelectric elements connected to a support block and extending in each direction, and being capable of walking operation relative to the movable table by the operations of the respective piezoelectric actuators. An alignment accuracy up to a nanometer level can be attained, and the alignment device itself and therefore the entire apparatus incorporating the alignment device can be significantly reduced in thickness and size.

Description

The present invention relates to an alignment device which can position an object to be positioned at a high accuracy within a target accuracy, and specifically to a device suitable for alignment in an apparatus such as a mounting apparatus or an exposure apparatus for wafers, etc.BACKGROUND ART OF THE INVENTIONFor example, in a mounting apparatus for bonding wafers to each other, an aligner for positioning a wafer at a predetermined position in order to processing the wafer or mounting a chip or other parts on the wafer, or an exposure apparatus for performing a predetermined exposure on a wafer, it is necessary to position the wafer at a predetermined position with a high accuracy. As a conventional alignment device used for such positioning of an object to be positioned, for example, used is a device wherein tables adjustable in position in X-axis and Y-axis directions (a horizontal direction) and .theta. direction (a rotational direction) are stacked and as needed a table or a h...

AI Technical Summary

Benefits of technology

Achieves high-accuracy positioning up to the nanometer level, reduces apparatus size, and enhances drive efficiency, allowing precise alignment of large objects without mechanical guide errors.

Problems solved by technology

In such a conventional alignment device, however, because the adjustment is carried out in order with respect to the respective directions (for example, X-axis and Y-axis directions and .theta. direction), even if a relatively high-accuracy positioning becomes possible only in one direction, there is a case where the positioning accuracy in the direction already adjusted goes wrong when the positioning in the other directions is performed, and consequently, the final positioning accuracy is limited.

Further, since usually a mechanical guide is used for positioning, there is a limit in the accuracy of the guide, and also from this point of view, the final positioning accuracy is limited.

More concretely, in a conventional alignment device, the possible positioning accuracy is an accuracy which cannot expect a submicron-level positioning, and therefore, a several-ten nanometer-level or several nanometer-level positioning is impossible by the conventional possible positioning accuracy.

Further, as aforementioned, since a conventional alignment device is constructed by stacking tables adjustable in position in X-axis and Y-axis directions and .theta. direction, when an axis A except an uppermost axis is adjusted, an axis stacked above the axis A must be driven, and therefore, the efficiency of the drive and control for positioning is not good.

Moreover, when the device is constructed by stacking tables adjustable in position in X-axis and Y-axis directions and .theta. direction, the thickness (the size in the vertical direction) of the entire alignment device increases, and therefore, an apparatus incorporating this alignment device, for example, a mounting apparatus or an exposure apparatus, inevitably becomes large-sized.

Further, because the distance from a guide to an uppermost positioning surface becomes large, an error of the guide is amplified, and this may give a bad influence to the positioning accuracy.

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